1. Field of the Invention
The present invention relates generally to a portable terminal using an asynchronous mobile communication system, and in particular, to an apparatus and a method for checking time and date information of an area in which a portable terminal using an asynchronous mobile communication system is currently positioned.
2. Description of the Related Art
Mobile communication technology was abruptly developed with the common use of cellular phones in the early 1980s. A Universal Mobile Telecommunication System (UMTS) has been developed and serviced based on the mobile communication technology in order to allow portable terminal users or computer users to transmit voice, video, and multimedia data at a high speed of 2 Mbps or more.
The UMTS has been commonly serviced in many countries throughout the world, has increased a number of subscribers thereto, and has been standardized in the 3rd Generation Partnership Project (3GPP). The UMTS can effectively provide higher speed data and/or multimedia services than an existing 2nd Generation communication system. The UMTS is also expected to be used throughout the world and thus can provide an international roaming function in any place.
A portable terminal, which supports such a UMTS, supports a Global System for Mobile Communication (GSM) system and the UMTS to change a network mode and maintain communications according to signals received from the GSM system and the UMTS.
The term “network mode” refers to a network environment that can be set and used in a portable terminal. For example, the network mode means an environment that is set to use a UMTS network mode together with a GSM network mode or use only the UMTS network mode or the GSM network mode during a call connection in a portable terminal.
In contrast to a portable terminal using an asynchronous mobile communication system that receives a satellite signal to provide current time and date information, the above-mentioned portable terminal does not receive a satellite signal. Thus, a user must directly set a current time or receive Mobility Management (MM) information from a Base Station (BS) to set current time in the above-mentioned portable terminal.
In the asynchronous mobile communication system, the user must directly set a time whenever the user moves from one area to another area, and the BS determines the local time, e.g., when Daylight Saving Time starts or ends, to provide time information. Thus, the time information, e.g., the current time, the current date, etc., cannot be set.
Accordingly, there is required an apparatus and a method for providing time and date information according to a request of a user in a portable terminal used in the asynchronous mobile communication system.